Autophagy promotes survival in aging submerged cultures of the filamentous fungus Aspergillus niger
| Autor: | Anne-Marie Burggraaf-van Welzen, Benjamin M. Nitsche, Gerda E. M. Lamers, Vera Meyer, Arthur F. J. Ram |
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| Rok vydání: | 2013 |
| Předmět: |
Programmed cell death
Microbial Viability Atg1 biology Nitrogen ATG8 Autophagy Aspergillus niger Hyphae Cellular homeostasis Hydrogen Peroxide General Medicine Vacuole biology.organism_classification Applied Microbiology and Biotechnology Carbon Culture Media Cell biology Fungal Proteins Oxidative Stress Biochemistry Mitophagy Biotechnology |
| Zdroj: | Applied Microbiology and Biotechnology. 97:8205-8218 |
| ISSN: | 1432-0614 0175-7598 |
| DOI: | 10.1007/s00253-013-4971-1 |
| Popis: | Autophagy is a well-conserved catabolic process constitutively active in eukaryotes that is involved in maintaining cellular homeostasis by the targeting of cytoplasmic content and organelles to vacuoles. Autophagy is strongly induced by the limitation of nutrients including carbon, nitrogen, and oxygen and is clearly associated with cell death. It has been demonstrated that the accumulation of empty hyphal compartments and cryptic growth in carbon-starved submerged cultures of the filamentous fungus Aspergillus niger is accompanied by a joint transcriptional induction of autophagy genes. This study examines the role of autophagy by deleting the atg1, atg8, and atg17 orthologs in A. niger and phenotypically analyzing the deletion mutants in surface and submerged cultures. The results indicate that atg1 and atg8 are essential for efficient autophagy, whereas deletion of atg17 has little to no effect on autophagy in A. niger. Depending on the kind of oxidative stress confronted with, autophagy deficiency renders A. niger either more resistant (menadione) or more sensitive (H2O2) to oxidative stress. Fluorescence microscopy showed that mitochondrial turnover upon carbon depletion in submerged cultures is severely blocked in autophagy-impaired A. niger mutants. Furthermore, automated image analysis demonstrated that autophagy promotes survival in maintained carbon-starved cultures of A. niger. Taken together, the results suggest that besides its function in nutrient recycling, autophagy plays important roles in physiological adaptation by organelle turnover and protection against cell death upon carbon depletion in submerged cultures. |
| Databáze: | OpenAIRE |
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